Overbalanced fluid-pressure valve.



B. P. NOYBS.

OVERBALANGED FLUID PRESSURE VALVE.

APPLICATION FILED JULY 8, 1910.

Patented May 2, 1911.

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UNITED s'rATEs PATENT OFFICE.

EDWARD r. NOYES, -or WINCHESTER, MASSACHUSETTS, assreu'on r0 0 r- POWERCOMPANY, or NEWARK, NEW JERSEY, A CORPORATION OF NEW JERSEY.

OVERBALANCED FLUID-PRESSURE VALVE.

Specification of Letters Patent.

Patented May 2, 1911.

Original application filed February 26, 1919, Serial No. 546,133.Divided and this application filed July 8, 1910. Serial No. 570,974.

To all whom 'it may concern:

Be itknown that I, EDWARD P. NoYEs, a citizen of the United States,residing at VVipchester, in the county of Middlesex and State ofMassachusetts, have invented certain new and useful Improvements inOverbalanced Fluid-Pressure Valves, of which the following is aspecification.

This invention relates to valves adapted.

to be actuated mechanically and also by the pressure of the fluidcontrolled by the valve, and its object is to provide a valve which ispredisposed by the pressures. acting thereon when at or near closure togo to or remain on its seat, but possessing such capability of controlof the acting pressures as to enable the valve when desired to beunseated with the exertion of a moderate mechanical force. The valve mayfurther have provision for bringing into play an additional fluid forcein the regions of wider opening, which force may be of such moment as toovercome the normal tendency toward closure and thus hold the valveopen.

This application-is' divided from my co pending application Serial No.546,133, filed February 26,1910.

Of the accompanying drawings, Figure 1 represents a vertical sectionalview of a. valve device constructed according to my as an inlet oranterior chamber, and an outlet or posterior chamber 3, the two beingconnected by a port 4 surrounded by a valve-seat 5 with which thesingle-seating main valve 6 cooperates. This valve is formed upon amoving piece or member 7 which also has a motor piston 8W0rking in acylinder 9 of the valve casing, and furthermore this piece has atelescopic connection with a hearing or guidelO which depends from thedetachable cover 11 of the cylinder. Thereby are formed two chambers 12,13 on the upper or valve-closing side of the member 7, the former beingan annular intermediate-pressure or controlling chamber surrounding thetelescopic connection, and the latter chamber 13 being abalancingchamber, so-called because when opened to the pressure in the posteriorchamber 3 a substantial part oft-he area of the main valve 6 is balancedas to posterior pressure.

The intermediate chamber 12 has a restricted inlet from anterior chamber2 by way of a small aperture 14formed in the piston 8 (or through anyother suitable opening'such as that which may be formed by making thepiston 8 a loose fit in its cylinder in the well-known manner), and ithas an outlet to the balancing chamber 13 by way of a duct 15 formed inthe cylinder cover' and a port 16 controlled by the tapered pllot valve17 and the superjacent close-fitting piston portion 18 formed on anoperating stem 19, the latter having suit able operating connectionssuch as thee-levers 20, 21 and the connecting linkage as shown.

An outlet from balancing chamber 13 to the posterior chamber 3-is;provided by way of a port 22 formed in an extension stem piece 28 ofthe member 7 having its bearing in a guide 24, and thisoutlet iscontrolled by a pilot valve 25 formed on the lower end of stem 19. Saidstem also has a boss or shoulder 26 adapted to abut againstacomplemental shoulder 27 formed on the memher 7, there being some lostmotion. in order that the initial upward movement of stem 19 shallmerely open the pilot valve .25, while further upward movement causesthe main valve to be positively lifted from its seat.

The dotted extension lines aa represent the diameter of the bearing 10of the telescopic connection, or the smaller diameter .of chamber 12,the lines b-J) represent the The diameter b-b being greater than 1 aa,it follows that the effective or projected area of member 7 exposed tothe downward or valve-closing pressure in chamber 12 exceeds that ofsaid member exposed to the upward or valve-opening pressure in chamber 2by an area a-b. This area 1 term an over-balancing annulus for thereason that when pressures are equalized in the anterior andintermediate chambers 2, 12 on the one hand, and the posterior andbalancing chambers 3,13 on the other hand, the main valve will be heldto its seat by fluid pressure, the annulus a'b being exposed in adownward direction to the pressure in chamber 12 and in an upward di-.

. relation to the diameter of the main valve port 4 (so long of courseas it is not made so large as to -obliterate the chamber 13) thusaffording any desired measure of closing pressure-force, regardless ofthe size of the main valve.

In operation, assuming the main and pilot' valves to be. closed asshown, the anterior pressure will accumulate in thechambers 12 and13 byleakage past the sliding surfaces or other leakage inlets thereto, andthus the main valve will be held to its seat by this pressure actingoverthe whole of the upper surface of member 7, opposed only by the anteriorpressure acting on the under side of piston 8, since the posteriorpressure 111 chamber 3 will supposedly have fallen away. Then to openthe main valve the stem 19 will be raised so as to open pilotvalve 25,and this will blow down the pressure in the balancing chamber 13 to thatof the posterior chamber 3. The main valve still tends to remain on itsseat, but with a greatly lessened pressure since all the areas have beenbalanced except that of annulus (Z -b, and this force can be readilyovercome by a further upward movement of stem 19 which through theshoulders '26, 27 causes the main valve to be mechanically lifted fromits seat.

If the opening of the main valve increases the posterior pressure, as ofcourse will generally be the case, the net downward or closing pressureon annulus ab decreasesin consequence, and this decrease continues asthe posterior pressure continues to rise.

The first part of the upward movement of stem 19 leaves the pistonportion 18 there- 'of in the port 16, and hence the. pressure in chamber12 remains the same as the an terior pressure, but at a certain point inthe rise of stem 19 the tapered valve 17 begins to open and partly dropthe pressure in chamber 12', in consequence of which thedownwardly-acting forces may .soon become smaller than theupwardly-acting forces, causing the main'valve-to be automaticallyopened wider, its tendency to go to an extreme opening however, beingretarded or arrested by the reaction of the rising posterior ressurewhich tends to check the drop oi pressure in 12. W hen-once thepreponderance of upward pressure has been es tablished by a suitableopening of pilotvalve 17, the main valve, without further mechanicalassistance from stem 19, tends to gradually attain a wider opening untilthe balance of acting forces has been restored, and the amount of thisopcning'may be made to depend upon the amount of opening of the valve17.

The amountof lost motion between stem 19 and member 7, as well as thedegree of taper of valve 17 and other features of design atlecting theconstruction 'or operation may of course be suitably arranged as.desired. v

To produce a closure of the main valve, the stem 19 is depressed, thusat first constricting and finally closing port 16, so that pressureaccumulates in chamber 12 (checked in its rapidity howe'ver by thefalling posterior pressure so long as port 16 is open) and forces theshoulder 27 against shoulder 26, so that the main valve may be seated byfluid pressure under the mechanical restraint of stem 19. During suchclosing movement, the overbalancing activity of annulus abcomes againinto play with increasing eifeet. Vhen the. main valve is seated, afurther downward movement of stem 19 seals the port 22 and all flow tothe posterior chamber 3 will then be stopped.

Fig. 2 represents a construction in which the piston annulus bo of Fig.1 is omitted together with the cylinder in which piston 8 works andthepilot valve controlling the outlet from chamber 12 above said piston.In other words the additional motor force which is brought into play bycontrolling the pressure above said piston is absent in Fig. 2.. Thedevice then becomes simply. an overbalancedsingle-seating valve providedwith the balancing chamber 13, whereby the valve-seating pressure whichaccumulates when the valve is closed may be relieved over a greater orless area of the main valve, and provided with the pilot stem having aloose mechanical connection with the main valve. This type possesses theadvantage over exactly-balanced or under-balanced valves, that it isheld to its seat by fluid ressure even when the pressure is relieved inthe balancing chamber (although it may be opened against said seatingpressure with moderate inltial and decreasing final effort) it is moreadaptable to use in other than vertical positions, and itsclosure isplaced more fully under the control of the stem 19, because if theoverbalancing annulus a--?) is relatively large enough to overcome thestatic forces such as friction (and gravity when the valve is inverted)the valve will close without being pushed by the stem and having thefluid-pressureconditions upset by the pilot-valve closure which suchpushing entails.

The structural embodiment is of course subjectto considerable variationwithout departure from my invention.

I claim,

1. In valve apparatus, the combination of a casing and a member withsingle-seating main valve, together forming a balancing chamber providedwith an outlet tothe posterior side of the valve, whereby pressure whichaccumulates in said chamber when its outlet is closed may be relieved topermit the opening of the' valve without having to overcome the anteriorpressure over its whole area, said member having an overbalancing areawhereby it is held seated when the pressure in said chamber is relieved,and operating means provided with a pilot valve which controls saidoutlet and having a lost-motion connection with the main valve wherebythe latter may be opened by a continuation of the outlet-openingmovement of said means.

2. In valve apparatus, the combination of.

a casing having anterior and posterior chambers connected by a port, amovable member telescoping with the casing and having a main valve whichcontrols the connection between said chambers and closes in thedirection of flow, said member forming with the casing a balancingchamber having an outlet to the posterior chamber through said memberand an inlet wherethrough it receives pressure fluid from the anteriorchamber, the effective valve-closing area of said member exposed in saidbalancing'chamber being less than the effective area of the main valveexposed to posterior pressure, and an operating stem having alost-motion connection with said member for opening the main valve whenthe stem is moved relatively thereto in one direction and provided witha pilot valve which closes saidoutlet when the stem is relatively moveddirection.

3. In fluid-pressure valve apparatus, the

area of the valve, said chamber providedwith an outlet to the posteriorside of the valve and adapted to accumulate the pressure anterior to.the valve when said outlet is closed, and a controlling chamber havingan inlet for the anterior pressure and an outlet, one of which isadjustable'in' size, and means for controlling the outlet of thebalancing chamber and for mechanically controlling said main-valvemember.

4. In valve apparatus, the combination of a casing having anterior andposterior chambers connected by a port, a movable member telescopicallyconnected with said casing and forming therewith an intermediate chambersurrounding the telescopic connection and in shunt between the anteriorand posterior in the opposite lieving the pressures on saidvalve-closing chambers, said member having a main valve controllin' saidport and a motor piston interposedetween the anterior and intermediatechambers, the etfective area of the piston adjacent to the intermediatechamber, being greater than the eflective-area of said member adjacentto the anterior chamber, and means for controlling the relation betweenthe inflow to and the outflow from said intermediate chamber. v

5. Valve apparatus comprising a casing having anterior and posteriorchambers connected by a port, a movable member telescopically connectedwith said casing and forming therewith an intermediate chambersurroundingthe telescopic connection and having a restricted inlet fromthe anterior chamber, and a balancing chamber having an inlet from theintermediate chamber'and an outlet to the posterior chamber, said memberprovided with a main valve controlling said port and a motor pistoninterposed between the anterior and intermediate chambers, the effectivearea of the piston exposed to intermediate pressure being greater thanthe effective area of said member exposedv to anterior pressure, and twopilot valves controlling respectively the inlet to and the outlet fromsaid balancing chamber.

6. Valve-apparatus comprising a valvecasing having anterior andposterior chambers connected by a port, a movable member having a mainvalve controlling said port, a valve-opening area, a valve-closing areaopposed-thereto and a second valve-closing area less than the posteriorarea of the main valve, and an operating stem having a lostmotionconnection with said member for positively opening the main valve, andhaving also serially-acting pilot valves for reareas.

7. Valve-apparatus comprising a. casing having anterior and posteriorchambers conhas an effective valve-closing area smaller I than theeffective posterior area of the valve, said balancing chamber providedwith an inlet from the intermediate chamber, and an outlet to theposterior chamber through the web of the movable member, and a stemadapted to positively open the main valve and carrying a pilot valvewhich controls the inlet from the intermediate to the balancing chamberand also carrying a second pilot valve adapted to seat on the web of themovable member and seal the outlet from the balancing chamber to theposterior chamber. a

' 8. Valve-apparatus comprising a casing having anterior and posteriorchambers connected by a port, and a guide member, a movable membertelescoping with said guide member and forming with the casing anintermediate chamber having an inlet from the anterior chamber, and abalancing chamber having an inlet from the intermediate chamber througha passage within said guide member, said movable member provided with amain valve controlling said port, a web located between the balancingchamber and the posterior chamber and formed with 'a port connecting thetwo, and

a motor piston interposed between the anterior and intermediate chambersand having an effective area exposed to the latter, greater than theeffective area of the movable member exposed to anterior pressure, and apilot stem having a loose mechanical connection with said movable memberfor positively opening the main valve and formed with a valvecontrolling said pas sage within the guide,. an adjacent piston portionadapted to enter and close said assage, and a second pilot valve adapteto close the port in said web.

In testimony whereof I have hereunto set my hand in the presence of twosubscribing witnesses, this thirtieth day of June, 1910.

EDWARD P. NOYES Wit-nesses:.

R. M. PIERSON, ARTHUR H. BROWN.

